function cross(w,rect,width)
%
%Screen('Preference', 'SkipSyncTests', 1)
%Screen('Preference', 'Verbosity', 0)
%[w,rect]=Screen('OpenWindow',0,125,[ 0 0 1000 800 ]) 
if nargin<1
    w=10;
end
if nargin<2
    rect=Screen('Rect',w);
end
[X,Y]=RectCenter(rect);
if nargin<3
    width = 30;
end
% FixCross = [X-1,Y-30,X+1,Y+30;X-30,Y-1,X+30,Y+1];
% Screen('FillRect', w, , FixCross');
% WaitSecs(0.5)
width = round(width/2)*2;





Screen('DrawLine',w,[255,255,255], X-width/2, Y, X+width/2, Y);
Screen('DrawLine',w,[255,255,255], X, Y-width/2, X, Y+width/2);
